2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #ifndef _LINUX_CPUFREQ_H
12 #define _LINUX_CPUFREQ_H
14 #include <linux/clk.h>
15 #include <linux/cpumask.h>
16 #include <linux/completion.h>
17 #include <linux/kobject.h>
18 #include <linux/notifier.h>
19 #include <linux/spinlock.h>
20 #include <linux/sysfs.h>
22 /*********************************************************************
24 *********************************************************************/
26 * Frequency values here are CPU kHz
28 * Maximum transition latency is in nanoseconds - if it's unknown,
29 * CPUFREQ_ETERNAL shall be used.
32 #define CPUFREQ_ETERNAL (-1)
33 #define CPUFREQ_NAME_LEN 16
34 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
35 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
37 struct cpufreq_governor;
39 struct cpufreq_freqs {
40 unsigned int cpu; /* cpu nr */
43 u8 flags; /* flags of cpufreq_driver, see below. */
46 struct cpufreq_cpuinfo {
47 unsigned int max_freq;
48 unsigned int min_freq;
50 /* in 10^(-9) s = nanoseconds */
51 unsigned int transition_latency;
54 struct cpufreq_real_policy {
55 unsigned int min; /* in kHz */
56 unsigned int max; /* in kHz */
57 unsigned int policy; /* see above */
58 struct cpufreq_governor *governor; /* see below */
61 struct cpufreq_policy {
62 /* CPUs sharing clock, require sw coordination */
63 cpumask_var_t cpus; /* Online CPUs only */
64 cpumask_var_t related_cpus; /* Online + Offline CPUs */
66 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
68 unsigned int cpu; /* cpu nr of CPU managing this policy */
69 unsigned int last_cpu; /* cpu nr of previous CPU that managed
72 struct cpufreq_cpuinfo cpuinfo;/* see above */
74 unsigned int min; /* in kHz */
75 unsigned int max; /* in kHz */
76 unsigned int cur; /* in kHz, only needed if cpufreq
77 * governors are used */
78 unsigned int suspend_freq; /* freq to set during suspend */
80 unsigned int policy; /* see above */
81 struct cpufreq_governor *governor; /* see below */
83 bool governor_enabled; /* governor start/stop flag */
85 struct work_struct update; /* if update_policy() needs to be
86 * called, but you're in IRQ context */
88 struct cpufreq_real_policy user_policy;
89 struct cpufreq_frequency_table *freq_table;
91 struct list_head policy_list;
93 struct completion kobj_unregister;
96 * The rules for this semaphore:
97 * - Any routine that wants to read from the policy structure will
98 * do a down_read on this semaphore.
99 * - Any routine that will write to the policy structure and/or may take away
100 * the policy altogether (eg. CPU hotplug), will hold this lock in write
101 * mode before doing so.
104 * - Lock should not be held across
105 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
107 struct rw_semaphore rwsem;
109 /* Synchronization for frequency transitions */
110 bool transition_ongoing; /* Tracks transition status */
111 spinlock_t transition_lock;
112 wait_queue_head_t transition_wait;
113 struct task_struct *transition_task; /* Task which is doing the transition */
117 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
118 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
119 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
120 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
122 #ifdef CONFIG_CPU_FREQ
123 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
124 void cpufreq_cpu_put(struct cpufreq_policy *policy);
126 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
130 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
133 static inline bool policy_is_shared(struct cpufreq_policy *policy)
135 return cpumask_weight(policy->cpus) > 1;
138 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
139 extern struct kobject *cpufreq_global_kobject;
140 int cpufreq_get_global_kobject(void);
141 void cpufreq_put_global_kobject(void);
142 int cpufreq_sysfs_create_file(const struct attribute *attr);
143 void cpufreq_sysfs_remove_file(const struct attribute *attr);
145 #ifdef CONFIG_CPU_FREQ
146 unsigned int cpufreq_get(unsigned int cpu);
147 unsigned int cpufreq_quick_get(unsigned int cpu);
148 unsigned int cpufreq_quick_get_max(unsigned int cpu);
149 void disable_cpufreq(void);
151 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
152 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
153 int cpufreq_update_policy(unsigned int cpu);
154 bool have_governor_per_policy(void);
155 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
157 static inline unsigned int cpufreq_get(unsigned int cpu)
161 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
165 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
169 static inline void disable_cpufreq(void) { }
172 /*********************************************************************
173 * CPUFREQ DRIVER INTERFACE *
174 *********************************************************************/
176 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
177 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
180 struct attribute attr;
181 ssize_t (*show)(struct cpufreq_policy *, char *);
182 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
185 #define cpufreq_freq_attr_ro(_name) \
186 static struct freq_attr _name = \
187 __ATTR(_name, 0444, show_##_name, NULL)
189 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
190 static struct freq_attr _name = \
191 __ATTR(_name, _perm, show_##_name, NULL)
193 #define cpufreq_freq_attr_rw(_name) \
194 static struct freq_attr _name = \
195 __ATTR(_name, 0644, show_##_name, store_##_name)
198 struct attribute attr;
199 ssize_t (*show)(struct kobject *kobj,
200 struct attribute *attr, char *buf);
201 ssize_t (*store)(struct kobject *a, struct attribute *b,
202 const char *c, size_t count);
205 #define define_one_global_ro(_name) \
206 static struct global_attr _name = \
207 __ATTR(_name, 0444, show_##_name, NULL)
209 #define define_one_global_rw(_name) \
210 static struct global_attr _name = \
211 __ATTR(_name, 0644, show_##_name, store_##_name)
214 struct cpufreq_driver {
215 char name[CPUFREQ_NAME_LEN];
218 /* needed by all drivers */
219 int (*init) (struct cpufreq_policy *policy);
220 int (*verify) (struct cpufreq_policy *policy);
222 /* define one out of two */
223 int (*setpolicy) (struct cpufreq_policy *policy);
224 int (*target) (struct cpufreq_policy *policy, /* Deprecated */
225 unsigned int target_freq,
226 unsigned int relation);
227 int (*target_index) (struct cpufreq_policy *policy,
230 /* should be defined, if possible */
231 unsigned int (*get) (unsigned int cpu);
234 int (*bios_limit) (int cpu, unsigned int *limit);
236 int (*exit) (struct cpufreq_policy *policy);
237 void (*stop_cpu) (struct cpufreq_policy *policy);
238 int (*suspend) (struct cpufreq_policy *policy);
239 int (*resume) (struct cpufreq_policy *policy);
240 struct freq_attr **attr;
242 /* platform specific boost support code */
243 bool boost_supported;
245 int (*set_boost) (int state);
249 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
250 all ->init() calls failed */
251 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
252 kernel "constants" aren't
253 affected by frequency
255 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
259 * This should be set by platforms having multiple clock-domains, i.e.
260 * supporting multiple policies. With this sysfs directories of governor would
261 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
262 * governor with different tunables for different clusters.
264 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
267 * Driver will do POSTCHANGE notifications from outside of their ->target()
268 * routine and so must set cpufreq_driver->flags with this flag, so that core
269 * can handle them specially.
271 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
274 * Set by drivers which want cpufreq core to check if CPU is running at a
275 * frequency present in freq-table exposed by the driver. For these drivers if
276 * CPU is found running at an out of table freq, we will try to set it to a freq
277 * from the table. And if that fails, we will stop further boot process by
278 * issuing a BUG_ON().
280 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
282 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
283 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
285 const char *cpufreq_get_current_driver(void);
287 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
288 unsigned int min, unsigned int max)
290 if (policy->min < min)
292 if (policy->max < min)
294 if (policy->min > max)
296 if (policy->max > max)
298 if (policy->min > policy->max)
299 policy->min = policy->max;
304 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
306 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
307 policy->cpuinfo.max_freq);
310 #ifdef CONFIG_CPU_FREQ
311 void cpufreq_suspend(void);
312 void cpufreq_resume(void);
313 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
315 static inline void cpufreq_suspend(void) {}
316 static inline void cpufreq_resume(void) {}
319 /*********************************************************************
320 * CPUFREQ NOTIFIER INTERFACE *
321 *********************************************************************/
323 #define CPUFREQ_TRANSITION_NOTIFIER (0)
324 #define CPUFREQ_POLICY_NOTIFIER (1)
326 /* Transition notifiers */
327 #define CPUFREQ_PRECHANGE (0)
328 #define CPUFREQ_POSTCHANGE (1)
330 /* Policy Notifiers */
331 #define CPUFREQ_ADJUST (0)
332 #define CPUFREQ_INCOMPATIBLE (1)
333 #define CPUFREQ_NOTIFY (2)
334 #define CPUFREQ_START (3)
335 #define CPUFREQ_UPDATE_POLICY_CPU (4)
336 #define CPUFREQ_CREATE_POLICY (5)
337 #define CPUFREQ_REMOVE_POLICY (6)
339 #ifdef CONFIG_CPU_FREQ
340 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
341 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
343 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
344 struct cpufreq_freqs *freqs);
345 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
346 struct cpufreq_freqs *freqs, int transition_failed);
348 #else /* CONFIG_CPU_FREQ */
349 static inline int cpufreq_register_notifier(struct notifier_block *nb,
354 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
359 #endif /* !CONFIG_CPU_FREQ */
362 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
369 * new = old * mult / div
371 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
374 #if BITS_PER_LONG == 32
375 u64 result = ((u64) old) * ((u64) mult);
377 return (unsigned long) result;
379 #elif BITS_PER_LONG == 64
380 unsigned long result = old * ((u64) mult);
386 /*********************************************************************
387 * CPUFREQ GOVERNORS *
388 *********************************************************************/
391 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
392 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
393 * two generic policies are available:
395 #define CPUFREQ_POLICY_POWERSAVE (1)
396 #define CPUFREQ_POLICY_PERFORMANCE (2)
398 /* Governor Events */
399 #define CPUFREQ_GOV_START 1
400 #define CPUFREQ_GOV_STOP 2
401 #define CPUFREQ_GOV_LIMITS 3
402 #define CPUFREQ_GOV_POLICY_INIT 4
403 #define CPUFREQ_GOV_POLICY_EXIT 5
405 struct cpufreq_governor {
406 char name[CPUFREQ_NAME_LEN];
408 int (*governor) (struct cpufreq_policy *policy,
410 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
412 int (*store_setspeed) (struct cpufreq_policy *policy,
414 unsigned int max_transition_latency; /* HW must be able to switch to
415 next freq faster than this value in nano secs or we
416 will fallback to performance governor */
417 struct list_head governor_list;
418 struct module *owner;
421 /* Pass a target to the cpufreq driver */
422 int cpufreq_driver_target(struct cpufreq_policy *policy,
423 unsigned int target_freq,
424 unsigned int relation);
425 int __cpufreq_driver_target(struct cpufreq_policy *policy,
426 unsigned int target_freq,
427 unsigned int relation);
428 int cpufreq_register_governor(struct cpufreq_governor *governor);
429 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
431 /* CPUFREQ DEFAULT GOVERNOR */
433 * Performance governor is fallback governor if any other gov failed to auto
434 * load due latency restrictions
436 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
437 extern struct cpufreq_governor cpufreq_gov_performance;
439 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
440 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
441 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
442 extern struct cpufreq_governor cpufreq_gov_powersave;
443 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
444 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
445 extern struct cpufreq_governor cpufreq_gov_userspace;
446 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
447 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
448 extern struct cpufreq_governor cpufreq_gov_ondemand;
449 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
450 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
451 extern struct cpufreq_governor cpufreq_gov_conservative;
452 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
455 /*********************************************************************
456 * FREQUENCY TABLE HELPERS *
457 *********************************************************************/
459 /* Special Values of .frequency field */
460 #define CPUFREQ_ENTRY_INVALID ~0
461 #define CPUFREQ_TABLE_END ~1
462 /* Special Values of .flags field */
463 #define CPUFREQ_BOOST_FREQ (1 << 0)
465 struct cpufreq_frequency_table {
467 unsigned int driver_data; /* driver specific data, not used by core */
468 unsigned int frequency; /* kHz - doesn't need to be in ascending
472 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
473 int dev_pm_opp_init_cpufreq_table(struct device *dev,
474 struct cpufreq_frequency_table **table);
475 void dev_pm_opp_free_cpufreq_table(struct device *dev,
476 struct cpufreq_frequency_table **table);
478 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
479 struct cpufreq_frequency_table
485 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
486 struct cpufreq_frequency_table
492 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
494 while ((*pos)->frequency != CPUFREQ_TABLE_END)
495 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
503 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
504 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
505 * @table: the cpufreq_frequency_table * to iterate over.
508 #define cpufreq_for_each_entry(pos, table) \
509 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
512 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
513 * excluding CPUFREQ_ENTRY_INVALID frequencies.
514 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
515 * @table: the cpufreq_frequency_table * to iterate over.
518 #define cpufreq_for_each_valid_entry(pos, table) \
519 for (pos = table; cpufreq_next_valid(&pos); pos++)
521 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
522 struct cpufreq_frequency_table *table);
524 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
525 struct cpufreq_frequency_table *table);
526 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
528 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
529 struct cpufreq_frequency_table *table,
530 unsigned int target_freq,
531 unsigned int relation,
532 unsigned int *index);
533 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
536 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
538 #ifdef CONFIG_CPU_FREQ
539 int cpufreq_boost_trigger_state(int state);
540 int cpufreq_boost_supported(void);
541 int cpufreq_boost_enabled(void);
543 static inline int cpufreq_boost_trigger_state(int state)
547 static inline int cpufreq_boost_supported(void)
551 static inline int cpufreq_boost_enabled(void)
556 /* the following funtion is for cpufreq core use only */
557 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
559 /* the following are really really optional */
560 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
561 extern struct freq_attr *cpufreq_generic_attr[];
562 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
563 struct cpufreq_frequency_table *table);
565 unsigned int cpufreq_generic_get(unsigned int cpu);
566 int cpufreq_generic_init(struct cpufreq_policy *policy,
567 struct cpufreq_frequency_table *table,
568 unsigned int transition_latency);
569 #endif /* _LINUX_CPUFREQ_H */